This is directed to a shipping container and the blanks for the container.
One type of container used as a shipping container is a regular slotted container known as an RSC. It is the blank 10 shown in FIG. 1 and the container 11 shown in FIG. 2. It has side walls 12 and 13 and end walls 14 and 15 attached to each other by score lines. An attachment panel 16 is attached to side wall 12 by a score line. The attachment panel 16 is glued to end panel 15 in the finished container. Closure flaps 17, 18, 19 and 20 are attached by score lines on the upper and lower edges of the side walls 12 and 13, and closure flaps 21, 22, 23 and 24 are attached to the upper and lower edges of end walls 14 and 15.
In forming the container for use, the container is opened from a lay-flat position and the lower closure flaps 19, 20, 23 and 24 are folded in and fastened together. The container is filled and the upper closure flaps 17, 18, 21 and 22 are folded in and fastened together. The top and bottom end panel closure flaps are usually covered by the side panel closure flaps.
Another type of container used as a shipping container is a bliss box. The blanks for one type of bliss box are shown in FIGS. 3 and 4 and the bliss box shown in FIG. 5. FIG. 3 shows the body blank 30 which has a side wall 31, bottom wall 32 and side wall 33 connected by score lines. Flaps 34, 35 and 36 are attached to each side of walls 31, 32 and 33, respectively, by score lines. There may be hand holes 37 in the side walls 31 and 33. The hand holes 37 are optional.
FIG. 4 shows the blank for the end walls 30′. The bliss box is formed by attaching the end walls blank 30′ to the body blank 30 by the flaps 34, 35 and 36.
The bliss box may have a telescoping cover. The blank 40 for the cover is shown in FIG. 6. The blank 40 has attachment panel 41 and side wall 42, end wall 43, side wall 44 and end wall 45 separated by score lines. There may be hand holes 46 in side walls 42 and 44 which match the hand holes 37 when the cover is placed over the container. Cover panels 47, 48, 49 and 50 are attached to the side walls 42, 43, 44 and 45 by score lines. In forming the cover the attachment panel 41 is attached to the outer edge of wall 45. The cover panels 48 and 50 are bent downwardly and the cover panels 47 and 49 are bent downwardly over them. The cover panels are attached to each other.
The cover is telescoped over the container in the packed bliss box.
FIG. 7 shows another type of end wall 35′. This end wall has flaps 38 and 39 attached to each side of the end wall 35′ by score lines. In the formed container the flaps 38 and 39 may be attached to the inner side of side walls 31 and 33.
Another type of container is the double cover container. The blanks for this container are shown in FIGS. 8 and 9 and the container is shown in FIG. 10. The blank 80 for the body has side walls 81, 82, 83 and 84 and attachment panel 85 connected by score lines. The attachment panel 85 is attached to the outer edge of side wall 81. The attachment panel is optional. The walls may be joined by a tape 94 holding side wall 81 to side wall 84. The blank 86 for the upper and lower lids has a central panel 87 and two pair of opposed side panels 88 and 89 attached to the four sides of the central panel 87 by score lines. Tabs 90 are attached to the side edges of two opposed side panels 88 by score lines. When the lids 92 are formed the tabs 70 are bent inwardly and attached to the opposed side panels 89. The lids 92 are telescoped over the body 93 and usually strapped in place.
For storage and transport the containers are stacked several high so stacking strength is necessary. A container should hold the containers above it without transferring the load to the contained product and its deformation should be minimal.
A corrugated container has a wall made of central flutes made of corrugating medium held in place by outer liners glued to the flutes. The flutes will normally extend vertically in the filled container to provide stacking strength. The actual stacking strength will depend on the size of the flute and the weight of the corrugating medium and the weight of the liners.
There are several size flutes. Some flute sizes are A flute which has 36 flutes per lineal flute and is 3/16 inch from flute tip to flute tip; B flute which has 51 flutes per lineal flute and is 3/32 inch from flute tip to flute tip; C flute which has 39 to 42 flutes per lineal flute and is 9/64 inch from flute tip to flute tip; and E flute which has 96 flutes per lineal flute and is 3/64 inch from flute tip to flute tip.
Basis weights for corrugating medium are from 16 to 40 pounds per thousand square feet. Basis weights for liner are from 20 to 96 per thousand square feet.
It should be understood that the higher basis weights increase the cost of a container.
The stacking strength may also be increased by using multiwall board. The board may be double wall with an external liner, a corrugated medium, a central liner, another corrugated medium and another outer liner. The board may be triple wall with an outer liner, a corrugating medium, an inner liner, a second corrugating medium, another inner liner, another corrugating medium and another external liner. The medium may be any flute size and the weights of the various elements may be the same or different. Again, the addition of the additional material increases the cost of the container.
After much research, and many trials it has been discovered that there is a simple way of increasing the stacking strength of a container without increasing the basis weight of the various elements of the container, or increasing the number of walls of the container.